Work positioning apparatus



Aug. 7,

1945 L MEISTER.

WORK POSITIONING APPARATUS Filed Sept. 18, 1942 @www Patented Aug. 7, 1945` 'UNITED WORK rosrrIoNiNG APPARATUS Leo Meister, Irvington, N. J.

Application september 18,1942, serial No. 458,907 A (onse-1) (Granted under the act 'of March 3, 1883, as

amended April'30, 1928; 37'() O.`G. 757) Claims.

This invention relates to work positioning apl paratus such as used in mass production to hold a work-piece in position while the tool performs its operation on the work. It deals. particularly with the handling of explosive charges in ammunition manufacture.

Work in ammunition factories yis constantly painstaking and time consuming because of the necessity for care in the handling of explosive ingredients and mixtures. Efforts are. continually being made to eliminate the human factor in the lhandling of explosives, because human practice ismost likely tovary from a safe and established procedure. The loading of primer cups isl one of the many phases of explosive manufacture which Arequire care in handling, ,and in which speed is-also important.

i l Itis an object of this invention to provide apparatus to aid in positioning and holding va primer cup loading'adapter while it is being operated on by a tool such as a compressing plunger, and to facilitate in releasing the adapter from that position when the` compressing operation has beenv completed. However, the apparatus is not limited to such an application.

This object is achieved by an indexing member consisting of a block having' a V-shaped recess to receive the adapter. An electromagnet at the vertex of the V is energized when a cam on the plunger closes a switch as the plunger approaches the adapter. The switch is held closed until the plunger again withdraws, when another cam trips a switch to momentarily energize a second electromagnet, positioned along one side of the V, to pull the adapter 'out of the operating position into a position where it can be engaged by hand with comparative safety.

The specilic nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawing in which:

Fig. 1 of the drawing shows the work positioning apparatus of the invention and its connections in the electrical con-trol circuits.

Fig. 2 is a plan View of the recessed platen with its -cover plate removed.

Fig. 3 is a longitudinal center section through the platen and cover member.

Fig. 4; is a longitudinal center section through 55 the recessed member.

the platen, sho-wing the cover separated `from Fig. 5 is a perspective view oi the recessed platen, with the cover member removed.

Referring to vthe drawing. in detail,l a work positioning member2 is shown as made' up of a recessed platen 4 and ,a cooperating cover member 5, held to a supporting table 8 by screws I0. Screws I t preferably extend upward fronivthe underside of the table, and preferably do. not extend through tothe upper side of the indexing member, to avoid small cracksor recesses where a dangerous concentration of powder might accumulate.

Platen 4 has a holding recess or stop I2Vwhich is generally V-shaped as seen from above. A It which has, preferably, the general shape of a horseshoe is provided at the vertex of the V-shaped stop,'and a second horseshoe recess I6 is provided in one side of the V of the stop. Electromagnets I8 and 2li are `disposed in recesses Ill and i6 respectively; magnet` I8 serves as a holding magnet and magnetr 20 serves as a moving magnet, as will be shown. The leads for magnet I8 are connected to switch 22, and the leads for magnet 20 are connected to switch 24. A compressing plunger 26 carries cams 28 and 3G to close switches 22 and 2.4, respectively. Any suitable `electric power source 32 may be providedto energize the magnets. Plunger 26 will, of course, have the desired shape of the tool required for the work to be done. In the present case, this tool is a plunger, as shown, for operation onl a primer cup loading adapter, such as the one shown at 34, which is in position to be operated upon by the plunger when it is in rm contact with both sides of the V -shaped stop.

Cover member 6 has projections 36 which fit into the horseshoe shaped recesses to hold the magnets in place.

Operation-Switch 24 will preferably be one which is closed only by movement of cam 39 past the switch in the upward direction. Therefore, when the adapter 34 isput approximately in place by being pushed manually into the V, movement of plunger 26 downward will not energize magnet 20, thus magnet 2i] will not disturb the positioning of the adapter. As the plunger continues to advance'down'ward, cam 28 closes switch 22, energizing magnet I8, which remains energized during the powder compressing action, securely holding the adapter in place. Furthermore, the eiect of the magnet is to hold the adapter down, as well as tight in against the V, so that the adapter is securely and effectively held in place during withdrawal of the plunger. As the plunger continues to rise, cam 28 moves out of engagement with switch 22, and magnet I8 is deenergized. With continued upward movement of the plunger, cam 30 trips switch 24, momentarily energizing magnet 2D. This momentary energization of magnet gives an impulse to adapter 34, pulling it in the direction of the magnet. However, since the magnet is energized only momentarily, the adapter is free to slide past the magnet by virtue of its inertia. It is then in a position where it may be safely and securely grasped with the ngers for removal.

If the design of the machine is such that the plunger does not permit the addition of cams, the same results may also be obtained by connecting two switches in the same circuit, but working with the movement of a foot pedal. On the down movement of the foot pedal a switch is closed energizing center magnet, and on the up movement the outer magnet is energized. The pedal is normally in switch olf position.

It will be noted that the work supporting portion of the platen presents a smooth imperforate surface, there being no openings in which powder dust might accumulate, and possibly cause trouble.

I claim:

1. Apparatus for positioning and holding a Work piece of magnetizable material, comprising a Work supporting platen having a reentrant V- shaped stop, a recess in the platen adjacent the Vertex of the stop, a magnet in said recess and arranged to exert its attractive forces at the said vertex of the stop to position and hold the work, a second magnet to one side of the vertex of the stop exerting its attractive forces in a region removed from the said vertex to remove the work from said vertex, and means for alterately energizing and deenergizing the magnets for the purpose specified.

2. The invention of claim l, characterized in that the means for alternately energizing and deenergizing the magnets, comprises a reciprocating tool having two cams thereon, a source of .electric energy for each magnet, an electric `circuit for each magnet, a switch in each circuit, one controlling the positioning and holding magnet, and the other the work removing magnet, one cam operating upon the switch for yenergizing the holding magnet, and the other cam operating' upon the other switch upon the withdrawal of the tool to deenergize the work holding magnet and energize the work removing magnet.

3. Apparatus for positioning and holding a work piece of magnetizable material, comprising a work supporting platen having a reentrant V- shaped stop, a recess at the vertex of the stop, magnetic means in said recess arranged to exert its attractive forces in the region of the said vertex to hold the work in operative position at said vertex, a .tool movable to operate upon the work, means carried by the tool for making the first mentioned means effective, another magnetic means in a region removed from the said vertex and also arranged to exert its attractive forces in a region removed from said vertex to remove the work from operative position in the said vertex, and means carried by the tool to render said first means ineffective upon the withdrawal of the tool and the second means eective to remove the work from operative position.

4. An apparatus for positioning and holding a work piece of magnetizable material, comprising a work supporting platen having a reentrant V- shaped stop, a work-holding and positioning magnet in the platen near the vertex of the recess and exerting its attractive forces in the region thereof, a work removing magnet alongside the irst and also exerting its attractive forces along the sides of the stop to remove the work piece from said vertex, a source of electric energy, an electric circuit for each magnet and a normally open switch in each circuit, a reciprocating tool for operating upon the work piece and means actuated by the tool to control the switches to alternately energize and deenergize the magnets.

5. Apparatus for positioning and holding a work piece of magnetiza-ble material, comprising a platen having a reentrant V-shaped stop, magnetic means in the platen exerting its attractive forces at the vertex of said stop for positioning and holding the work piece in operative position of said vertex, another magnetic means exerting its force along a side of said stop to remove the work from operative position, means for energizing the work holding magnet, and means for energizing the work removing magnet, said means being separate and operating to energize the removing magnet after deenergizing the holding magnet.

LEO MEISTER. 

